Wrong value of ExtMin

[NirVidP]

I have received the attached drawing from one of my clients. (I have removed geometry to maintain confidentiality. But it retains the essence of problem that I have). I have to write VB/A program that extracts data from this drawing. For that I need to know the extents of the drawing.

The system variable ExtMin shows a value of X (98331) which is greater than the X (92817) of min. point (left bottom corner of the border) of existing geometry.

I have tried everything (purge, overkill, audit, recover) but can't find a way to correct the value of ExtMin.

Assuming that this drawing is corrupt and can't be recovered, then I have another problem. How can I programatically find that the ExtMin value of this drawing is wrong and hence this drawing is corrupt.

 

[NirVidP]

OK.
On digging deeper I found that the current UCS of the drawing was "*NO NAME*". When I manually changed if to "World" then ExtMin value was correct.
Now my problem is how to find out, in VBA, that the drawing is using an unsaved UCS as the current UCS. Because in both cases the value of UCSNAME is "".
Also in both cases ThisDrawing.CurrentUCS returns a null object. ThisDrawing.UserCoordinateSystems.Count is also 0.